CVE-2026-16038 json
MStore API < 4.21.0 - Unauthenticated Payment Bypass via Multiple Payment Gateways
published 2026-08-07 3 mo ago modified 2026-08-26 2 mo ago also EUVD-2026-54386
- cvss
- 9.1
- version 3.1, CNA
- cisa kev
- Not listed
- not in CISA's catalog
- epss
- 0.4%
- EPSS 0.4% chance of exploitation in 30 days, percentile 36%
- public exploits
- 0
- none known
Summary
The MStore API WordPress plugin before 4.21.0 does not verify the payment with the payment gateway before marking an order as paid on several of its payment-completion endpoints, allowing an unauthenticated attacker to mark an arbitrary order fully paid without paying and obtain goods or services for free.
Patch / fix
- Unknown MStore API 4.21.0
CISA SSVC
- Exploitation
- Proof of concept is public
- Automatable
- yes
- Technical impact
- total
- Assessed
- 3 mo ago
Exploit prediction
0.42% chance of exploitation in the next 30 days, higher than 36% of all scored CVEs (FIRST EPSS, 2026-11-08).
Exploits and checks
- wpscan.com https://wpscan.com/vulnerability/6321d247-39c7-43a6-a528-202e1118a5d5/ referenced PoC, tagged "exploit" by a source, unverified
CVSS scores
| assigned by | version | score | vector |
|---|---|---|---|
| CISA ADP | 3.1 | 9.1 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N |
| CNA | 3.1 | 9.1 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N |
Affected products
- Unknown MStore API
Classification
- Weakness
-
- CWE-862 Missing Authorization
- Technology feeds
References
-
wpscan.com
/vulnerability/6321d247-39c7-43a6-a528-202e1118a5d5/
exploit, vdb-entry, technical-description
Sources
- CVE List CVE-2026-16038
- NVD CVE-2026-16038
Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.
CPEs and fixed versions use Anchore's correction of NVD's data: Added CPE configurations because not yet analyzed by NVD.